High-heat-resistant resins are suitably used in applications that require high heat resistance, such as applications of engine covers for automobiles or the like, and electric insulation applications such as encapsulation materials for power semiconductors.
Polymers of cyclic olefins such as norbornenes are generally excellent in heat resistance, and as the techniques of producing a norbornene-based crosslinked polymer having even more improved heat resistance, for example, a method using a given norbornene-based monomer having a polar group (Patent Publication 1) or a method using a given metathesis catalyst (Patent Publication 2) has been proposed. However, there are still rooms for improvements in heat resistance of the polymers obtained.